Function wrapSpans

src/ui/diff/renderRows.tsx:302–359

Wrap styled spans into visual lines while preserving color runs across splits.

(spans: RenderSpan[], width: number)

/** Wrap styled spans into visual lines while preserving color runs across splits. */
function wrapSpans(spans: RenderSpan[], width: number) {
  if (width <= 0) {
    return [[]] as RenderSpan[][];
  }

  const lines: RenderSpan[][] = [[]];
  let current = lines[0]!;
  let remaining = width;

  for (const span of sanitizeTerminalSpans(spans)) {
    const spanWidth = measureTextWidth(span.text);
    if (spanWidth === 0) {
      appendRenderSpan(current, span);
      continue;
    }

    let offset = 0;

    while (offset < spanWidth) {
      if (remaining <= 0) {
        current = [];
        lines.push(current);
        remaining = width;
      }

      const visible = sliceTextByWidth(span.text, offset, remaining);
      if (visible.width === 0) {
        // A single wide cluster cannot fit in the remaining cells; continue on the next row.
        current = [];
        lines.push(current);
        remaining = width;
        const forced = sliceTextByWidth(span.text, offset, width);
        if (forced.width === 0) {
          break;
        }
        const nextSpan = {
          ...span,
          text: forced.text,
        };
        current.push(nextSpan);
        offset += forced.width;
        remaining = Math.max(0, width - forced.width);
        continue;
      }

      const nextSpan = {
        ...span,
        text: visible.text,
      };
      appendRenderSpan(current, nextSpan);

      offset += visible.width;
      remaining -= visible.width;
    }
  }

  return lines;
}